Information processing apparatus, information processing method, storage medium, and information processing system

ABSTRACT

An apparatus includes an acquisition unit configured to acquire a measurement result of a golf swing motion, and a calculation unit configured to calculate a behavior of a shot by the golf swing motion. The measurement result includes a head speed, an incident angle, and a face angle at the time of striking. The behavior includes an initial speed, a vertical launch angle, and a back spin amount. The calculation unit calculates the behavior by substituting the head speed, the incident angle, and the face angle, all of which have been acquired by the acquisition unit, into a predetermined arithmetic formula having a plurality of variables including at least a head speed, an incident angle, and a face angle at the time of striking of a golf club head.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and the benefit of Japanese Patent Application No. 2019-116596 filed on Jun. 24, 2019, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an information processing technique concerning behavior analysis in the golf field.

Description of the Related Art

There are various techniques for analyzing a swing motion of a golfer. Japanese Patent Laid-Open No. 2017-023638 discloses a technique of measuring the incident angle and the like of a golf club head and analyzing a swing motion. Japanese Patent Laid-Open No. 2017-023639 discloses a technique of measuring the rotation angle and the like of a golf club and analyzing a swing motion. Japanese Patent Laid-Open No. 2017-070366 discloses a technique of estimating a striking position on a face surface at the time of striking. Japanese Patent Laid-Open No. 2017-000179 discloses a technique of analyzing the behavior of a golf club head and predicting the ball flight of a shot. There is also proposed a technique of recommending a golf item suitable for a golfer based on such analysis result (for example, Japanese Patent Laid-Open No. 2011-015968).

The behavior of a shot such as the initial speed, launch angle, and spin amount of a golf ball immediately after striking is one of matters of high concern for a golfer. In general, the behavior of a shot is actually measured by a measuring facility such as a camera or a doppler radar. If there is no such measuring facility, the golfer cannot know the behavior of a shot as a result of his/her swing motion. Japanese Patent Laid-Open No. 2017-000179 proposes a technique of predicting the ball flight of a shot. However, the technique predicts the behavior of a golf club head, and analyzes a collision of the head with a golf ball, and thus calculation is complicated.

SUMMARY OF THE INVENTION

The present invention has as its object to provide a technique of estimating the behavior of a shot without requiring a measuring facility such as a camera or a doppler radar.

According to an aspect of the present invention, there is provided an information processing apparatus comprising: an acquisition unit configured to acquire a measurement result of a golf swing motion of a golfer; and a calculation unit configured to calculate a behavior of a shot by the golf swing motion, wherein the measurement result includes a head speed, an incident angle, and a face angle at the time of striking of a golf club head, the behavior of the shot includes an initial speed, a vertical launch angle, and a back spin amount, and the calculation unit calculates the behavior of the shot by substituting the head speed, the incident angle, and the face angle, all of which have been acquired by the acquisition unit, into a predetermined arithmetic formula having a plurality of variables including at least a head speed, an incident angle, and a face angle at the time of striking of a golf club head.

Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an information processing system according to an embodiment of the present invention;

FIG. 2A is an explanatory view of an incident angle;

FIG. 2B is an explanatory view of a face angle;

FIG. 3A is an explanatory view of distinction of a striking position;

FIG. 3B is an explanatory view showing an example of a method of measuring a striking position;

FIGS. 4A and 4B are explanatory views of the launch angles of a shot;

FIGS. 5A and 5B are explanatory views of the spin amounts of a shot;

FIGS. 5C and 5D are explanatory views of ball flight;

FIG. 6A is a flowchart illustrating an example of the processing of a computer when generating an arithmetic formula by performing machine learning;

FIG. 6B is a flowchart illustrating an example of the processing of an information processing apparatus;

FIG. 7 is a view showing an example of a method of selecting a recommended golf item;

FIGS. 8A and 8B are graphs each showing an example of a method of selecting a recommended golf item;

FIG. 9 is a view showing examples of a plurality of kinds of arithmetic formulas; and

FIG. 10 is a view showing another example of a system.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention, and limitation is not made an invention that requires all combinations of features described in the embodiments. Two or more of the multiple features described in the embodiments may be combined as appropriate. Furthermore, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.

First Embodiment

<Arrangement of System>

FIG. 1 is a schematic view of an information processing system 1 according to an embodiment of the present invention. The system 1 includes a measuring apparatus 2, an information processing apparatus 3, a display device 4, and an input device 5. Arrows X, Y, and Z represent a three-dimensional coordinate system recognized or set by the measuring apparatus 2. The arrows X and Y represent horizontal directions orthogonal to each other, and the arrow Z represents the vertical direction. The arrow X represents the target line direction of a golf ball.

The measuring apparatus 2 is an apparatus that measures a golf swing motion of a golfer 10. In this embodiment, the measuring apparatus 2 is an apparatus that measures the behavior of a golf club 100. The golf club 100 includes a head 101 having a face surface (striking surface) 101 a, and a shaft 102 connected to the head 101. A grip (not shown) is attached to the end portion of the shaft 102 on the side of the golfer 10. The measuring apparatus 2 is an apparatus attached to the shaft 102 (or grip) of the golf club 100, and includes an acceleration sensor and an angular velocity sensor. As the measuring apparatus 2, for example, TSND121 available from ATR-Promotions or M-tracer available from Seiko Epson Corporation can be used. As a result of detection of the measuring apparatus 2, time-series data of the three-dimensional acceleration and three-dimensional angular velocity of the golf club 100 during a swing are obtained.

The information processing apparatus 3 is a computer that estimates, from the measurement result of the measuring apparatus 2 and the like, the behavior of a shot of a golf ball 200 struck by a golf swing motion of the golfer 10 with the golf club 100. The information processing apparatus according to this embodiment also has a function of recommending a golf item suitable for the golfer 10 based on the estimated behavior of the shot. The golf item includes a golf club or a golf ball. The information processing apparatus 3 includes a processing unit 31, a storage unit 32, and an I/F unit (interface unit) 33 which are electrically connected to each other. The processing unit 31 is a processor such as a CPU. The storage unit 32 includes one or a plurality of storage devices. The storage devices are, for example, a RAM, a ROM, and a hard disk. The storage unit 32 stores a program to be executed by the processing unit 31, and various kinds of data. The program to be executed by the processing unit 31 can be formed from a plurality of instructions readable by the processing unit 31.

The I/F unit 33 inputs/outputs data between an external device and the processing unit 31. The I/F unit 33 can include an I/O interface and a communication interface. The measuring apparatus 2 is communicably connected to the information processing apparatus 3 by wired or wireless communication, and the measurement result is acquired by the information processing apparatus 3.

The display device 4 and the input device 5 are connected to the information processing apparatus 3. The display device 4 is, for example, an electronic image display device such as a liquid crystal display device, and displays the processing result of the information processing apparatus 3. The input device 5 includes a mouse and a keyboard, and accepts a data input and an operation instruction for the information processing apparatus 3. The display device 4 may be a device having an information input function like a touch panel. In this case, the input device 5 need not be provided.

<Estimation of Behavior of Shot>

The ball flight of the golf ball 200 struck by a golf swing motion of the golfer 10 is important for him/her. The ball flight of the golf ball is estimated based on the behavior of the shot such as the initial speed, the vertical and horizontal launch angles, the back spin amount, and the side spin amount of the golf ball 200 immediately after striking. The behavior of the shot can be actually measured by a measuring facility such as a camera or a doppler radar. In this embodiment, however, the behavior of the shot is estimated based on the measurement result of the measuring apparatus 2 or the like without requiring any such measuring facility.

<Generation of Arithmetic Formula>

In this embodiment, the behavior of the golf ball 200 is estimated by an arithmetic formula (model) having the measurement result of the golf swing motion of the golfer 10 and the like as explanatory variables and the behavior of the golf ball 200 immediately after striking as a target variable. As an advance preparation, an arithmetic formula is generated.

As the explanatory variables, the measurement result of the golf swing motion of the golfer 10, the attributes of the golfer 10, and the attributes of a golf item can be used. The measurement result of the golf swing motion can include a measurement result obtained by the measuring apparatus 2 or another measurement method. The measurement result obtained by the measuring apparatus 2 can include the head speed of the head 101 at the time of striking, the incident angle of the head 101, and the face angle at the time of striking. FIG. 2A is an explanatory view of the incident angle, and FIG. 2B is an explanatory view of the face angle.

Referring to FIG. 2A, the incident angle is the angle of the trajectory of the head 101 in the Z direction at the time of striking the golf ball 200 with respect to the X direction on the X-Z plane. In an example shown in FIG. 2A, a direction D1 of the head trajectory is specified based on the position of the head 101 a predetermined time before an impact timing and a position X1 of the head 101 at the time of striking, and an angle θ1 between the direction D1 and the X direction represents the incident angle. In the example shown in FIG. 2A, the upward direction is set as the positive direction, and the downward direction is set as the negative direction. A striking timing can be measured by the measuring apparatus 2 based on a change in acceleration of the golf club 100. The position of the head 101 at this time corresponds to the position X1 of the head 101 at the time of striking.

Referring to FIG. 2B, the face angle at the time of striking is in the direction of the face surface 101 a at the time of striking the golf ball 200. In an example shown in FIG. 2B, an angle θ2 formed by the Y direction and the face surface is set as the face angle on the X-Y plane. In terms of measurement by the measuring apparatus 2, the angle θ2 can be considered to be a reference (0°) at the time of calibration. For example, calibration indicates processing of causing the measuring apparatus 2 to recognize a target direction. In the example shown in FIG. 2B, an angle in a direction in which the face surface 101 a is opened is negative, and an angle in a direction in which the face surface is closed is positive.

The measurement result of the measuring apparatus 2 can additionally include a face rotation, a flexure return time, a loft angle at the time of striking, and a swing trajectory. The face rotation indicates a change degree of the face surface 101 a during a swing, and is, for example, a rotation amount around the axis of the shaft 102 per unit time immediately before striking. The unit time is, for example, 0.01 sec immediately before striking. The flexure return time indicates a time from when the acceleration of a predetermined portion (for example, the distal end portion of the grip) of the golf club becomes maximum until an impact. In general, during a golf swing, the shaft 102 has a tendency that it is flexed, after a down swing, in a direction in which the head 101 is behind the proximal end side, and decelerates on the proximal end side before striking, and then the flexure of the shaft 102 returns to reach an impact. The flexure return time can be regarded as a time until the flexure of the shaft 102 returns before striking. The loft angle at the time of striking indicates an angle between a vertical plane and the face surface 101 a at the time of striking on the X-Z plane. The swing trajectory indicates the angle of the trajectory of the head 101 in the Y direction at the time of striking the golf ball 200 with respect to the X direction on the X-Y plane.

The measurement result of the golf swing motion can additionally include the striking position of the golf ball 200 on the face surface 101 a. FIG. 3A is an explanatory view showing an example of digitization of the striking position. In an example shown in FIG. 3A, a striking position 101 b is specified in a coordinate system in which the face center of the face surface 101 a is set as the origin, and a toe-heel direction D2 and a vertical direction (crown-sole direction) D3 are set as coordinate axes. On the coordinate axis D2, for example, a positive value is set on the heel side. On the coordinate axis D3, for example, a positive value is set on the upper side (crown side). The striking position 101 b can be measured by the measuring apparatus 2 based on the rotation amount of the shaft 102 at the time of striking, a change in direction of the face surface 101 a, and the like. As shown in FIG. 3B, however, a marker 110 on which a striking mark of the golf ball 200 remains may be stuck on the face surface 101 a, thereby performing measurement. The face surface 101 a and the position of the golf ball 200 may be captured by a camera at the time of striking, and the striking position may be measured from a captured image.

The attributes of the golfer 10 can include the feature amounts of the golfer such as the sex, height, weight, and age. The attributes of the golf item can include the attributes of a golf club and those of a golf ball. The attributes of the golf club can include the feature amounts of the overall golf club, those of the shaft, those of the head, and those of the grip. The feature amounts of the overall golf club can include the total weight, balance, and product type of the golf club. The feature amounts of the shaft can include the length, rigidity, flex, torque, kick point, and weight. The feature amounts of the head can include the center-of-gravity depth, center-of-gravity height, center-of-gravity distance, center-of-gravity angle, loft angle, and weight. The feature amounts of the grip can include the weight and material.

With respect to the target variable of the behavior of the shot, the initial speed of the shot is the speed of the golf ball 200 immediately after striking. FIG. 4A is an explanatory view of the vertical launch angle, and FIG. 4B is an explanatory view of the horizontal launch angle. As shown in FIG. 4A, the vertical launch angle is an angle θ3 of the trajectory of the golf ball 200 in the Z direction immediately after striking with respect to the X direction on the X-Z plane. A position X2 indicates the initial position of the golf ball 200. In an example shown in FIG. 4A, the upper direction is set as the positive direction and the lower direction is set as the negative direction. As shown in FIG. 4B, the horizontal launch angle is an angle θ4 of the trajectory of the golf ball 200 in the Y direction immediately after striking with respect to the Y direction on the X-Y plane. In an example shown in FIG. 4B, the left direction is set as the positive direction and the right direction is set as the negative direction.

FIG. 5A is an explanatory view of the back spin amount. The back spin amount is the rotation amount of the golf ball 200 around the Y-axis immediately after striking. In an example shown in FIG. 5A, rotation in the upper direction is positive and rotation in the lower direction is negative. FIG. 5B is an explanatory view of the side spin amount. The side spin amount is the rotation amount of the golf ball 200 around the Z-axis immediately after striking. In an example shown in FIG. 5B, rotation in the hook direction is positive, and rotation in the slice direction is negative.

An arithmetic formula can be generated using an actual measured data group formed from an actual measured data group of the target variable corresponding to the above-described data group of the explanatory variables. The target variable is actually measured by the measuring facility such as a camera or a doppler radar. For example, TRACKMAN available from TRACKMAN can be used.

The arithmetic formula can be derived by, for example, machine learning using the actual measured data group as supervised data. FIG. 6A is a flowchart illustrating an example of the processing of a computer when deriving an arithmetic formula by performing machine learning on the computer. The computer used for machine learning may be the information processing apparatus 3 on which machine learning software is installed.

In step S1, the actual measured data group is loaded as supervised data. The actual measured data group can be accumulated in advance in an external storage device in a predetermined data format. In step S2, various settings of a learning method are made, and machine learning is executed based on the supervised data loaded in step S1. In step S3, an arithmetic formula is generated as a product. The generated arithmetic formula is stored in the storage unit 32 of the information processing apparatus 3, and used to estimate the behavior of the shot.

Examples of an algorithm of machine learning are linear regression using stochastic gradient descent, ridge regression, lasso regression, support vector regression, and deep learning. For linear regression using stochastic gradient descent, ridge regression, or lasso regression, when the target variable is represented by y, the explanatory variable is represented by x, and a coefficient is represented by a, a linear formula can be used as the arithmetic formula, given by:

y1=a1·x1+a2·x2+a3·x3 . . .

Then, the coefficient a is obtained by machine learning in step S2, thereby completing the arithmetic formula. For lasso regression or deep learning, the formula and the coefficients in the formula can be obtained by machine learning in step S2. For lasso regression, the type of explanatory variable used finally can also be determined by machine learning.

According to an experiment related to this embodiment, if, among the explanatory variables, especially the head speed, the incident angle of the head, and the face angle at the time of striking had high correlations with the behavior (the initial speed of the ball, the vertical and horizontal launch angles, the back spin amount, and the side spin amount) of the shot, and were used as explanatory variables, predetermined accuracy could be obtained with respect to estimation of the behavior of the shot. Therefore, at least the head speed and the face angle at the time of striking are adopted as explanatory variables. In this case, if the arithmetic formula is set by the above linear formula, for example,

initial speed of ball=a1·head speed+a2·incident angle+a3·face angle+a0

vertical launch angle=a11·head speed+a12·incident angle+a13·face angle+a10

Among the explanatory variables, the striking position also has high correlation with the behavior (the initial speed of the ball, the vertical and horizontal launch angles, the back spin amount, and the side spin amount) of the shot, thereby improving the estimation accuracy. In this case, if the arithmetic formula is set by the above linear formula, for example,

side spin amount=a21·head speed+a22·incident angle+a23·face angle+a24·striking position+a20

The explanatory variables used for the arithmetic formula are not limited them, as a matter of course. All or some of the attributes of the golfer or all or some of the attributes of the golf item may be included. With respect to the target variable, if the initial speed of the shot, the vertical launch angle, and the back spin amount are provided, the ball flight can be estimated accurately to some extent. If the horizontal launch angle and the side spin amount are further added, it is also possible to estimate the degree of left or right bending of the shot, thereby improving the estimation accuracy of the ball flight.

Note that the arithmetic formula may be derived by a method other than machine learning, for example, correlation analysis. For example, the arithmetic formulas may be derived from the actual measured data group by multiple regression analysis. For multiple regression analysis, by representing a coefficient by b, the arithmetic formulas can be given by:

initial speed of ball=head speed×(b0+b1·incident angle+b2·face angle+b3·√(striking position in direction D3)²+(striking position in direction D2)²)

vertical launch angle=b11×incident angle+b12·face angle+b13·striking position in direction D3+b10

back spin amount=b21·incident angle+b22·face angle+b23·striking position in direction D3+b20

horizontal launch angle=b31·swing trajectory+b32·face angle+b33·striking position in direction D3+b34·striking position in toe-heel direction

side spin amount=b41·incident angle+b42·swing trajectory+b43·face angle+b44·striking position in direction D2

<Estimation Processing and Selection of Recommended Item>

FIG. 6B shows an example of processing of estimating the behavior of the shot using the arithmetic formula obtained in the processing shown in FIG. 6A, and shows processing executed by the processing unit 31 of the information processing apparatus 3. In step S11, processing of accepting the explanatory variables to be used to estimate the behavior of the shot of this time is performed. More specifically, the measuring apparatus 2 is made to measure the swing motion of the golfer. In this example, the golfer 10 actually strikes the golf ball 200 by the golf club 100, and the measuring apparatus 2 measures the behavior of the golf club 100. A measurement result is stored in the storage unit 32. An operator can input the explanatory variables other than the measurement result of the measuring apparatus 2 using the input device 5, and the input contents are stored in the storage unit 32.

In step S12, the arithmetic formula stored in the storage unit 32 is read out. In step S13, the explanatory variables to be used for estimation of this time, which have been accepted in step S11, are read out. In step S14, the explanatory variables read out in step S13 are substituted into the arithmetic formula read out in step S12, thereby calculating the target variable. This can obtain the estimated value of the behavior of the shot.

In step S15, the ball flight of the shot is estimated based on the target variable calculated in step S14. An example of contents of the estimated ball flight can be a distance of the shot in the target line direction (X direction). FIG. 5C shows an example of the ball flight of the shot in the target line direction, and a distance from the position X2 to the position X3 indicates a carry (flight distance) and a distance from the position X3 to a position X4 indicates a run (a rolling distance on the ground). The distance of the shot may include only the carry or may be the total value of the carry and the run. An example of contents of the estimated ball flight can be a deflection of the shot in the horizontal direction (Y direction). FIG. 5D shows an example of the ball flight of the shot in the horizontal direction, in which a position Y1 indicates the initial position (striking position) of the golf ball 200. A broken line in the X direction passing through the position Y1 indicates a direction in which the ball is hit, and a deflection when the ball stops on this line is set to 0. In the example shown in FIG. 5D, the ball flight is deflected leftward.

Referring back to FIG. 6B, in step S16, a golf item suitable for the golfer is selected as a recommended item based on the estimated value of the behavior of the shot calculated in step S14 and the ball flight estimated in step S15. The recommended item is, for example, a golf club or a ball. For the golf club, the recommended item may be a part such as a shaft or head or a whole club. As a recommended item, an item having a characteristic that makes the estimated value of the behavior of the shot closer to a predetermined reference value (or ideal value), or an item having a characteristic that makes the ball flight of the shot closer to a predetermined ideal ball flight is basically selected. If, for example, the back spin amount or the side spin amount is larger than an ideal value, an item having a characteristic that suppresses the back spin amount is selected. If the vertical launch angle is smaller than an ideal value, an item having a characteristic that increases the launch angle is selected. If the deflection of the ball flight in the horizontal direction is large, an item having a characteristic that suppresses the deflection in the horizontal direction is selected.

Information for matching the golf item and the behavior of the shot or the estimation result of the ball flight is stored in the storage unit 32, and used to select a recommended item in step S16. FIG. 7 shows one example, and an example of the information for selecting a recommended golf ball. In the example shown in FIG. 7, the behavior of the shot is divided into five regions R1 to R5 by setting the vertical launch angle and the back spin amount as coordinate axes. The region R5 is a region of an ideal behavior with respect to the vertical launch angle and the back spin amount. A recommended golf ball corresponding to the region R5 is a product with standard specifications. The region R1 is a region of a behavior of a large launch angle and a large back spin amount. The region R1 is assigned with a golf ball product with specifications in which the ball is difficult to fly high and the back spin amount is suppressed, as compared with the product with the standard specifications.

The region R2 is a region of a behavior of a small launch angle and a large back spin amount. The region R2 is assigned with a golf ball product with specifications in which the ball is easy to fly high and the back spin amount is suppressed, as compared with the product with the standard specifications. The region R3 is a region of a behavior of a large launch angle and a small back spin amount. The region R3 is assigned with a golf ball product with specifications in which the ball is difficult to fly high and the back spin amount is increased, as compared with the product with the standard specifications. The region R4 is a region of a behavior of a small launch angle and a small back spin amount. The region R4 is assigned with a golf ball product with specifications in which the ball is easy to fly high and the back spin amount is increased, as compared with the product with the standard specifications.

FIGS. 8A and 8B show other examples of information used to select a recommended item. In an example shown in FIGS. 8A and 8B, the information shown in FIG. 8A or 8B is selected in accordance with the initial speed of the shot. For example, if the initial speed is higher than a threshold, the information shown in FIG. 8A is selected; otherwise, the information shown in FIG. 8B is selected.

In the example shown in FIGS. 8A and 8B, the behavior of the shot is divided into four regions by setting the vertical launch angle and the back spin amount as coordinate axes, and corresponding golf ball products BA to BC are assigned to the regions, respectively.

The golf ball product BA is, for example, a golf ball that has a soft core and a soft cover, and has a characteristic that it is easy to spin. The golf ball product BB is, for example, a golf ball that has a soft cover and a hard core, and has a characteristic that it is easy to spin. The golf ball product BC is, for example, a golf ball that has a soft core and a hard cover, and has a characteristic that it is difficult to spin.

For a golfer whose initial speed of a shot is higher than the threshold, power to crush the golf ball at the time of striking is large. In the example shown in FIG. 8A, the region corresponding to the product BB with the hard core is wide, and the regions corresponding to the golf ball products BA and BC having the characteristic that the core is soft are narrow so as not to be selected easily. Along with increases in launch angle and back spin amount, the recommended golf ball changes in an order of the products BA, BB, and BC.

The example shown in FIG. 8B in which the initial speed is equal to or lower than the threshold is the same as in FIG. 8A in that along with increases in launch angle and back spin amount, the recommended golf ball changes in an order of the products BA, BB, and BC but is different in that the regions corresponding to the products BA and BC each having the soft core are wide so the products are selected easily.

Referring back to FIG. 6B, in step S17, the information concerning the golf swing motion of this time is displayed on the display device 4. Examples of the displayed information are the values of the explanatory variables used for calculation, the value of the target variable as a calculation result, the ball flight estimation result in step S15, and the recommended item in step S16. Processing of one cycle thus ends.

Second Embodiment

In the first embodiment, the attributes of the golfer and those of the golf item have been exemplified as examples of the explanatory variables. However, a method of selecting one of arithmetic formulas respectively set for the attributes of a golfer and those of a golf item without using the attributes of the golfer and those of the golf item as explanatory variables may be adopted. FIG. 9 is an explanatory view of arithmetic formulas.

In an example shown in FIG. 9, each of arithmetic formulas A and B is generated in accordance with the attribute of a golfer, and is generated by particularly distinguishing between a male and a female. The arithmetic formula A is derived from a data group of a golf swing motion of a male golfer and an actual measured data group of the behavior of a corresponding shot. The arithmetic formula B is derived from a data group of a golf swing motion of a female golfer and an actual measured data group of the behavior of a corresponding shot.

In addition, each of arithmetic formulas M and K is generated in accordance with the attribute of a golf item. Each arithmetic formula is generated by distinguishing among golf ball products. The arithmetic formula M is derived from a data group of a golf swing motion of a golfer using a golf ball product X and an actual measured data group of the behavior of a corresponding shot. The arithmetic formula K is derived from a data group of a golf swing motion of a golfer using a golf ball product Y and an actual measured data group of the behavior of a corresponding shot.

In this embodiment, if the processing shown in FIG. 6B is performed, an input of information (for example, in the example shown in FIG. 9, a male, a female, or a golf ball product) for selecting the type of arithmetic formula is accepted in step S11. In step S12, an arithmetic formula corresponding to the information input in step S11 is read out. For example, in the case of the example of FIG. 9, if “male” is input in step S11, the arithmetic formula A is read out in step S12. If “golf ball product X” is input in step S11, the arithmetic formula M is read out in step S12. The subsequent processing is performed in accordance with the readout type of arithmetic formula.

Note that distinction of each arithmetic formula shown in FIG. 9 is merely an example. Each arithmetic formula may be distinguished and generated only based on the attribute of the golfer or based on the attribute of the golf item. Alternatively, each arithmetic formula may be distinguished and generated based on a combination of the attribute of the golfer and that of the golf item. An arithmetic formula corresponding to the combination is, for example, an arithmetic formula X for a male and a golf ball product A, or an arithmetic formula Z for a female and a golf ball product A.

The attribute of the golfer for distinguishing each arithmetic formula is not limited to the sex, and another attribute such as the height, weight, length of golf experience, or handicap may be used. Similarly, the attribute of the golf item for distinguishing each arithmetic formula is not limited to the golf ball product, and another attribute such as a golf club product, a head weight, a shaft flex, the layer structure of a ball, the spin characteristic of a ball, or the distance characteristic of a ball may be used.

Third Embodiment

In the system shown in FIG. 1, the measuring apparatus 2 and the information processing apparatus 3 are arranged in a relatively short distance, and the system can be installed in a store or the like. Another arrangement example can also be adopted. In addition, a measuring apparatus other than that shown in FIG. 1 can be adopted.

FIG. 10 exemplifies another example of the arrangement of an information processing system 1. In the example of the arrangement shown in FIG. 10, an information processing apparatus 3 serves as a server to communicate with a communication apparatus (a mobile terminal 301, a personal computer 302, or the like) via a network 300. The network 300 is, for example, the Internet.

An arrangement example EX1 on the measuring side includes the mobile terminal 301 and a measuring apparatus 2. This system is suitable for a golfer to individually estimate the behavior of a shot. The mobile terminal 301 is, for example, a smartphone, and has a short distance wireless communication function with the measuring apparatus 2 and a wireless communication function via the network 300 and a base station (not shown). The mobile terminal 301 transmits, to the information processing apparatus 3, the values of explanatory variables such as a measurement result received from the measuring apparatus 2. The information processing apparatus 3 calculates a target variable, and transmits each piece of information such as ball flight estimation or a recommended item to the mobile terminal 301. The mobile terminal 301 displays the received information. That is, the mobile terminal 301 executes processes in steps S11 and S17 of FIG. 6B, and the information processing apparatus 3 executes processes in steps S12 to S16 of FIG. 6B.

An arrangement example EX2 on the measuring side includes the personal computer 302 and a plurality of measuring apparatuses 2A. This system is suitable for measuring a golf swing motion in a golf shop or the like. Each measuring apparatus 2A is an image capturing apparatus such as a video camera. The personal computer 302 has a processing function for an image captured by each image capturing 2A, and a wireless communication function via the network 300. A golfer makes a test shot in a test shot box or the like. The testing golfer is captured from multiple directions by the plurality of image capturing apparatuses 2A in the test shot box or the like, thereby capturing the three-dimensional behavior of a golf club 100. The captured images are loaded into the personal computer 302 and analyzed, thereby deriving the values of explanatory variables. Furthermore, the personal computer 302 transmits the values of the explanatory variables to the information processing apparatus 3. The information processing apparatus 3 calculates a target variable, and transmits each piece of information such as ball flight estimation or a recommended item to the personal computer 302. The personal computer 302 displays the received information. That is, the personal computer 302 executes the processes in steps S11 and S17 of FIG. 6B, and the information processing apparatus 3 executes the processes in steps S12 to S16 of FIG. 6B.

The invention is not limited to the foregoing embodiments, and various variations/changes are possible within the spirit of the invention. 

What is claimed is:
 1. An information processing apparatus comprising: an acquisition unit configured to acquire a measurement result of a golf swing motion of a golfer; and a calculation unit configured to calculate a behavior of a shot by the golf swing motion, wherein the measurement result includes a head speed, an incident angle, and a face angle at the time of striking of a golf club head, the behavior of the shot includes an initial speed, a vertical launch angle, and a back spin amount, and the calculation unit calculates the behavior of the shot by substituting the head speed, the incident angle, and the face angle, all of which have been acquired by the acquisition unit, into a predetermined arithmetic formula having a plurality of variables including at least a head speed, an incident angle, and a face angle at the time of striking of a golf club head.
 2. The apparatus according to claim 1, further comprising a selection unit configured to select a golf item suitable for the golfer based on the behavior of the shot calculated by the calculation unit.
 3. The apparatus according to claim 1, wherein the behavior of the shot further includes a horizontal launch angle and a side spin amount.
 4. The apparatus according to claim 1, wherein the arithmetic formula is a formula derived from a first data group including the measurement results of a plurality of golfers and a second data group as actual measurement results of behaviors of shots by golf swing motions of the plurality of golfers.
 5. The apparatus according to claim 4, wherein the arithmetic formula is a formula derived by machine learning using the first data group and the second data group as supervised data.
 6. The apparatus according to claim 1, wherein the measurement result includes a striking position on a face surface of the golf club head, the plurality of variables include a striking position on a face surface of the golf club head, and the calculation unit calculates the behavior of the shot by substituting, into the arithmetic formula, the head speed, the incident angle, the face angle, and the striking position, all of which have been acquired by the acquisition unit.
 7. The apparatus according to claim 1, wherein the acquisition unit acquires an attribute of the golfer and an attribute of a golf item used by the golfer in the golf swing motion, the plurality of variables include an attribute of a golfer and an attribute of a golf item, and the calculation unit calculates the behavior of the shot by substituting, into the arithmetic formula, the head speed, the incident angle, the face angle, the attribute of the golfer, and the attribute of the golf item, all of which have been acquired by the acquisition unit.
 8. The apparatus according to claim 1, wherein the acquisition unit acquires an attribute of the golfer, as the arithmetic formula, there are a plurality of types of arithmetic formulas in correspondence with attributes of golfers, and the calculation unit selects an arithmetic formula for calculating the behavior of the shot from the plurality of types of arithmetic formulas in accordance with the attribute of the golfer acquired by the acquisition unit.
 9. The apparatus according to claim 1, wherein the acquisition unit acquires an attribute of a golf item used by the golfer in the golf swing motion, as the arithmetic formula, there are a plurality of types of arithmetic formulas in correspondence with attributes of golf items, and the calculation unit selects an arithmetic formula for calculating the behavior of the shot from the plurality of types of arithmetic formulas in accordance with the attribute of the golf item acquired by the acquisition unit.
 10. An information processing method comprising: causing a computer to acquire a measurement result of a golf swing motion of a golfer; and causing the computer to calculate a behavior of a shot by the golf swing motion, wherein the measurement result includes a head speed, an incident angle, and a face angle at the time of striking of a golf club head, the behavior of the shot includes an initial speed, a vertical launch angle, and a back spin amount, and in the causing the computer to calculate the behavior of the shot, the behavior of the shot is calculated by substituting the head speed, the incident angle, and the face angle, all of which have been acquired in the causing the computer to acquire the measurement result, into a predetermined arithmetic formula having a plurality of variables including at least a head speed, an incident angle, and a face angle at the time of striking of a golf club head.
 11. A storage medium storing a program for causing a computer to function as an acquisition unit configured to acquire a measurement result of a golf swing motion of a golfer, and a calculation unit configured to calculate a behavior of a shot by the golf swing motion, wherein the measurement result includes a head speed, an incident angle, and a face angle at the time of striking of a golf club head, the behavior of the shot includes an initial speed, a vertical launch angle, and a back spin amount, and the calculation unit calculates the behavior of the shot by substituting the head speed, the incident angle, and the face angle, all of which have been acquired by the acquisition unit, into a predetermined arithmetic formula having a plurality of variables including at least a head speed, an incident angle, and a face angle at the time of striking of a golf club head.
 12. An information processing system comprising: a measuring unit configured to measure a golf swing motion of a golfer; an acquisition unit configured to acquire a measurement result of the measuring unit; and a calculation unit configured to calculate a behavior of a shot by the golf swing motion, wherein the measurement result includes a head speed, an incident angle, and a face angle at the time of striking of a golf club head, the behavior of the shot includes an initial speed, a vertical launch angle, and a back spin amount, and the calculation unit calculates the behavior of the shot by substituting the head speed, the incident angle, and the face angle, all of which have been acquired by the acquisition unit, into a predetermined arithmetic formula having a plurality of variables including at least a head speed, an incident angle, and a face angle at the time of striking of a golf club head. 